The purpose of this study is to determine the feasibility and side effects of combining radioactive antibody therapy with additional external beam radiation after high dose chemotherapy, followed by autologous peripheral blood stem cell rescue in patients with metastatic prostate cancer who have demonstrated resistance to hormonal therapy. The first step is to obtain and store adequate hematopoietic stem cells. Patients will be given a high dose of chemotherapy to decrease tumor burden and stimulate the bone marrow to produce stem cells. They will also receive G-CSF, to shorten the period of neutropenia and enhance stem cell production. If the patients continue to meet eligibility requirements, they will then receive a dose of radioactive antibody CC49. Two days prior to receiving the antibody, they will be given an oral solution to keep the radioactive iodine from going to the thyroid and a hormone pill to suppress the thyroid. On the day of antibody administration, they will be given a test dose of non-radioactive antibody by injection, and observed for any allergic reaction. If an allergic reaction occurs, the infusion will be stopped and patients will be taken off study. If no allergic reaction occurs, the dose of radioactive monoclonal antibody will be infused over a period of 30 minutes. The patients will then be transferred to the Bone Marrow Transplantation Unit where they will be cared for while receiving total body radiation and autologous stem cell rescue.